Condensed Consolidated Statements of Income (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues
Sales	$ 1,577.2	$ 1,785.1
Other revenues	170.8	235.6
Total revenues	1,748.0	2,020.7
Costs and expenses
Operating costs and expenses	1,389.4	1,421.8
Depreciation, depletion and amortization	(170.7)	(142.9)
Asset retirement obligation expenses	19.0	15.0
Selling and administrative expenses	65.1	71.0
Other operating (income) loss:
Net gain on disposal or exchange of assets	(2.6)	(4.0)
Loss from equity affiliates	17.6	22.7
Operating profit	88.8	351.3
Interest expense	101.3	102.0
Interest income	(5.9)	(8.1)
(Loss) income from continuing operations before income taxes	6.6	(257.4)
Income tax provision	3.7	74.4
(Loss) income from continuing operations, net of income taxes	(10.3)	183.0
Loss from discontinued operations, net of income taxes	(9.1)	(4.7)
Net (loss) income	(19.4)	178.3
Less: Net income attributable to noncontrolling interests	4.0	5.6
Net (loss) income attributable to common stockholders	(23.4)	172.7
(Loss) income from continuing operations
Basic (loss) earnings per share	$ (0.05)	$ 0.65
Diluted (loss) earnings per share	$ (0.05)	$ 0.65
Net (loss) income attributable to common stockholders
Basic (loss) earnings per share	$ (0.09)	$ 0.63
Diluted (loss) earnings per share	$ (0.09)	$ 0.63
Dividends declared per share	$ 0.085	$ 0.085
Retained Earnings [Member]
Other operating (income) loss:
Net (loss) income	$ (23.4)